System and method of ink and data delivery

ABSTRACT

A system ( 100, 500, 600, 800 ) of ink and multi-channel data delivery includes an optically transmissive tubular body ( 113 ) having at least two ends ( 105, 107 ). The tubular body ( 113 ) defines an ink channel between an ink supply ( 101 ) and at least one inkjet pen ( 117, 521, 525, 529, 901, 903 ). A multi-channel optical transmitter ( 111, 300, 400 ) is in optical communication with one end ( 105, 107 ) of the tubular body ( 113 ), and an optical receiver ( 115, 509, 511, 513 ) is in optical communication with another end ( 105, 107 ) of the tubular body ( 113 ).

BACKGROUND

Ink tubes are used in many printing devices, including thermal inkjetprinters, piezoelectric inkjet printers, and other printing devices.Typically, these printing devices maintain a reserve of liquid ink in areservoir. Ink tubes are used to transport the ink from the reservoir tothe printing device's printhead or pens. The printhead, includingindividual pens, selectively deposits the ink onto a medium to createprinted text and images. In most cases, ink tubes are made out of aflexible plastic material that allows for a substantially nonlinear pathbetween the ink reservoir and the printhead.

Electronic control signals are generally transmitted from controlcircuitry in the printing device to electrical components in the inkjetpens. The control signals affect the operation of individual inkjetpens, such as when ink is selectively released from the pens onto printmedia. Wires or cables are generally used to electrically connect thecontrol circuitry to the related components in the inkjet pens.

Additionally, some printing devices include diagnostic system componentsdesigned to aid service personnel in identifying faulty components. Insome inkjet printers, for example, optical indicators such as lightemitting diodes (LEDs) are used to indicate faulty inkjet pens.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate various embodiments of theprinciples described herein and are a part of the specification. Theillustrated embodiments are merely examples and do not limit the scopeof the claims.

FIG. 1 is a diagram of an illustrative embodiment of a system of ink anddata delivery, according to principles described herein.

FIG. 2 is a cross-sectional diagram of an illustrative embodiment of atubular body for ink and data delivery, according to principlesdescribed herein.

FIG. 3 is a diagram of an illustrative embodiment of an opticaltransmitter, according to principles described herein.

FIG. 4 is a diagram of an illustrative embodiment of an opticaltransmitter, according to principles described herein.

FIG. 5 is a diagram of an illustrative embodiment of a system of ink anddata delivery, according to principles described herein.

FIG. 6 is a cross-sectional diagram of an illustrative embodiment of asystem of ink and data delivery, according to principles describedherein.

FIG. 7 is a diagram of an illustrative embodiment of a system of ink anddata delivery, according to principles described herein.

FIG. 8 is a diagram of an illustrative embodiment of a system of ink anddata delivery, according to principles described herein.

FIG. 9 is a diagram of an illustrative embodiment of a printing devicehaving a diagnostic indicator, according to principles described herein.

FIG. 10 is a flowchart of an illustrative embodiment of a method ofproviding a diagnostic indicator, according to principles describedherein.

FIG. 11 is a flowchart of an illustrative embodiment of a method of inkand data delivery, according to principles described herein.

Throughout the drawings, identical reference numbers designate similar,but not necessarily identical, elements.

DETAILED DESCRIPTION

As used in the present specification and in the appended claims, theterm “inkjet pen” refers broadly to a device configured to selectivelydeposit liquid ink onto a print medium in accordance with controlsignals received by the inkjet pen. Inkjet pens may comprise a varietyof different components to actuate the controlled deposition of inkdrops. For example, inkjet pens include, but are not limited to,piezo-electric inkjet pens, thermal inkjet pens and others.

As used in the present specification and in the appended claims, theterm “optical energy” refers to radiated energy having a wavelengthgenerally between 10 nanometers and 500 microns. Optical energy as thusdefined includes, but is not limited to, ultraviolet, visible, andinfrared light. A beam of optical energy may be referred to herein as a“light beam” or “optical beam.”

As used in the present specification and in the appended claims, theterm “optical source” refers to a device from which optical energyoriginates. Examples of optical sources as thus defined include, but arenot limited to, light emitting diodes, lasers, light bulbs, and lamps.

As used in the present specification and in the appended claims, theterm “optical transmitter” refers broadly to a device configured totransmit data, such as digital bits or analog signals, using one or moreoptical sources. In some cases, optical transmitters as thus definedmodulate the data onto light beams originating from the opticalsource(s) by varying specific characteristics of the light beams, suchas beam intensity, wavelength, or duration of beam pulse.

As mentioned above, ink tubes and electrical wires or cables are oftenused in printing devices to transport ink and data, respectively, toinkjet pens. The inkjet pens may then selectively deposit the ink onto aprint medium according to control data received via the electrical wiresor cables. However, it may be desirable to reduce the number of physicalcomponents present in the printing system that are used to transportdata and ink to the inkjet pen. Particularly, it may be desirable toprovide an ink transportation system having integrated data transmissioncapabilities. A reduced number of components may lower the cost offabricating the printing device and free up space within the printingdevice.

As also mentioned above, some printing devices include diagnostic systemcomponents designed to aid service personnel in identifying faultycomponents. In some inkjet printers, for example, optical indicatorssuch as light emitting diodes (LED) are used to indicate faulty inkjetpens. If internal systems determine that a particular inkjet pen ismalfunctioning, a signal is sent to light an LED disposed on that inkjetpen. Consequently, when a service technician accesses the interior ofthe printing system to repair or replace the malfunctioning pen, themalfunctioning pen is immediately identified by the lit LED, and thetechnician can immediately begin work on the malfunctioning pen.

While this arrangement is very helpful in identifying for the technicianwhich pen needs service, it may be desirable to provide a system ofdisplaying an optical service indicator on specific inkjet pens withoutrequiring the presence of discrete LEDs and their associated real estateon the pens. Furthermore, it may also be desirable to reduceelectromagnetic interference concerns, electrostatic discharge concerns,and concerns associated with differential ground shifts betweenelectronics at each on opposite ends of an ink tube.

Consequently, the present specification discloses systems of ink andmulti-channel data delivery in which data is transmitted optically overa plurality of channels to an inkjet pen through an optically conductivetubular body. The same tubular body may also serve to provide a flow ofink to the inkjet pen.

Additionally, the present specification discloses a system of visualdiagnostic indicators for an inkjet pen. The system includes a tubularbody having first and second ends. An optical source is in opticalcommunication with one of the ends, and the other end is in opticalcommunication with a visual indicator or optical illuminator on theinkjet pen. Light from the optical source is transmitted through thetubular body and lights the visual indicator on the inkjet pen whenneeded to indicate, for example, a detected malfunction in thatparticular inkjet pen.

In the following description, for purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of the present systems and methods. It will be apparent,however, to one skilled in the art that the present systems and methodsmay be practiced without these specific details. Reference in thespecification to “an embodiment,” “an example” or similar language meansthat a particular feature, structure, or characteristic described inconnection with the embodiment or example is included in at least thatone embodiment, but not necessarily in other embodiments. The variousinstances of the phrase “in one embodiment” or similar phrases invarious places in the specification are not necessarily all referring tothe same embodiment.

The principles disclosed herein will now be discussed with respect toillustrative systems and methods.

Illustrative Systems

Referring now to FIG. 1, a diagram of an illustrative system (100) ofink and multi-channel data delivery in a printing device is shown. Theillustrative system (100) includes a tubular body (113) having first andsecond ends (105, 107). The tubular body (113) is configured totransport liquid ink from an ink supply (101) to an inkjet pen (117),where the ink may then be selectively applied to a print medium by thepen (117). The tubular body (113) is coupled to an in-line ink pump(109) and an optical transmitter (111) at the first end. At the secondend (107), the tubular body (113) includes an optical receiver (115) andis coupled to the inkjet pen (117).

The in-line ink pump (109) is coupled to the ink supply (101) and isconfigured to mechanically force liquid ink from the ink supply (101)into the first end of tubular body (113) where the ink is provided underpressure to the inkjet pen (117) at the second end (107) of the tubularbody (113).

The tubular body (113) may be fabricated from a flexible material havingoptical properties that enable the transmission of light through thematerial of the sidewall of the tubular body (113) without significantloss of energy. Upon entering this material that composes the tubularbody (113), the index of refraction of the material is such that, insome embodiments, substantially total internal reflection of the beamoccurs, thus enabling the transmission of the optical beam along thelength of the tubular body (113) with minimal losses. In otherembodiments, the tubular body (113) may be lossy for certain types ofsignaling, given the relatively short distances of transmission. Even ifthe amplitude of the transmitted optical signal is significantly reducedwhen it reaches the optical receiver (115), as long as the receiver candetect the signal, the output of the receiver (115) may be amplified tothe appropriate level. Many plastic materials having these opticalproperties, such an appropriate index of refraction, are available inthe art. Additionally, custom plastics or other materials havingdesirable optical characteristics for use in the tubular body (113) maybe used in some embodiments.

Because transmitted optical beams are confined within the material ofthe tubular body (113), the tubular body (113) may be flexed orpositioned as needed according to the physical and spatialcharacteristics of the printing device. A linear or “line of sight”configuration between the optical transmitter (111) and the opticalreceiver (115) is not needed to ensure data transmission. Additionally,concerns stemming from electromagnetic interference, electrostaticdischarge, and differential ground shifts between electronics at eachend of the tubular body (113) are virtually eliminated by transmittingdata optically through the tubular body (113), as opposed toelectrically.

The tubular body (113) is configured to transmit multiple data channelsacross its length. The data channels may be transmitted together asdistinct beams of optical energy, each of the beams having acharacteristic wavelength that is separate and distinct from thecharacteristic wavelengths of other optical beams that are transmittedin the tubular body (113). Each of the separate optical beams may bemodulated with different data. In some embodiments, the multiplechannels of data transmitted through the tubular body (113) may be usedfor the purpose of increasing bandwidth or data integrity, with each ofthe data channels intended for the same destination. In otherembodiments, separate data channels may be intended for separatedestinations, such as different inkjet pens, and take advantage of acommon optical transmission medium in the tubular body (113).

The optical transmitter (111) in the system (100) is configured totransmit multiple channels of optical data into the tubular body (113)which conducts the optical data along its length to the optical receiver(115). In some embodiments, the optical transmitter (111) is aring-shaped structure having substantially the same cross-sectionalshape and size as the tubular body (113). The optical transmitter mayinclude one or more optical sources, such as LEDs, vertical cavitysurface emitting lasers (VCSELs), other lasers, from which the opticalbeams bearing the data originate.

In some embodiments, the optical transmitter (111) may include aplurality of optical sources, each source being configured to transmitan optical beam of a different characteristic wavelength. Bytransmitting data from each of the optical sources through the tubularbody (113), multiple channels of data may be transmitted through thetubular body (113). In other embodiments, the optical transmitter (111)may include one or more optical sources that are configured toselectively alter the characteristic wavelength of optical beamsoriginating from the sources, thus allowing the sources to transmitoptical energy at one characteristic wavelength at a given time, andswitch to a separate characteristic wavelength at another time.

The optical transmitter (111) is in communication with a modulatorelement (119) configured to encode digital or analog data onto the oneor more optical beams emitted by the optical source(s). The modulatorelement (119) is configured to provide a control signal to the opticaltransmitter (111) that affects the emission of the one or more opticalbeams by the optical transmitter (111) in addition to thecharacteristics of the beam(s). The modulator element (119) may encodedata onto the beam(s) by selectively altering a property of the opticalbeams according to the data to be encoded. For example, the intensity,duration, and/or frequency of the optical beams may be dynamicallyaltered by the modulator element (119) to encode data into the opticalbeam.

The optical receiver (115) in the system (100) is configured to receivemultiple channels of optical data from the tubular body (113). Like theoptical transmitter (111), the optical receiver (115) may, in someembodiments, be a ring-shaped structure with substantially the samecross-sectional area and size as the tubular body (113). The opticalreceiver (115) includes at least one sensor configured to detect opticalenergy transmitted through the tubular body (113). In some embodiments,the optical receiver may include a plurality of optical sensors, withindividual sensors being configured to detect optical energy having aspecific characteristic wavelength or ranges of wavelengths. In otherembodiments, the optical receiver may have one or more optical sensorsor detectors that are configured to receive optical beams of differentwavelengths at different times.

The sensors in the optical receiver (115) are configured to output anelectronic signal representative of the optical beams received throughthe tubular body (113). Examples of suitable optical sensors that may beincluded in the optical receiver include photodiodes, light-sensitivesemiconductors, and photodetectors. An optical sensor may be tuned todetect a certain wavelength or range of wavelengths of light usingfiltering techniques. In this way, multiple optical beams havingdifferent characteristic wavelengths may be transmitted together throughthe tubular body (113) and separately detected by the optical receiver(115).

The optical receiver (115) is in communication with a demodulatorelement (121) that is configured to extract the encoded data from theelectrical signal output by the detectors in the optical receiver (115).In some embodiments, separate channels of data may be extracted fromseparate optical beams by the demodulator element (121). In otherembodiments, multiple modulator elements (119) may be used inconjunction with corresponding multiple demodulator elements (121) totransmit the data across the tubular body (113).

In the system (100) shown, pen control signals are produced by printercontroller circuitry (123) to control the operation of the inkjet pen(117). These pen control signals may be in the form of digital or analogdata that is then encoded onto one or more optical beams using themodulator element (119) and the optical transmitter (111). The pencontrol signals are then transmitted optically from the first end (105)of the tubular body (113) to the second end (107) of the tubular body(113) where the optical beams are detected by the optical receiver (115)and demodulated by the demodulator element (121). The pen controlsignals are then received by the pen electronics (125) where they areused to control pen operations.

In addition to the transmission of data to the inkjet pen (117), thetubular body (113) may also be used by the pen electronics (125) to senddata to the printer control electronics (123). This data may includeinformation such as pen health, pen type installed, pen temperature,etc. Data transmission from pen (117) to controller (123) may co-existwith data transmission from controller (123) to pen (117).

In still other embodiments, the tubular body (113) may be used by theprinter control electronics (123) and an ink delivery system tocommunication with each other, possible concurrently. For example, theprinter control electronics (123) may send data to the IDS instructingthe system to increase pressure, prime tubes, illuminate diagnosticsLED, etc. The IDS may transmit data to the control electronics (123),such as types of supplies installed, ink level remaining, diagnosticinfo, and/or other pertinent data.

Referring now to FIG. 2, a cross-sectional view of the system (100)described in relation to FIG. 1 is shown. Illustrative paths (201, 202)of optical energy through the material of the tubular body (113) areshown as dotted lines going from the optical transmitter (111) to theoptical receiver (115). While optical energy may undergo numerousinternal reflections within the material of the tubular body (113)between the optical transmitter (111) and the optical receiver (115),the illustrative paths (201, 202) are shown as straight paths of averagedisplacement for clarity.

Additionally, the ink pump (109) includes further mechanical componentsto propel the ink from the ink supply into the tubular body (113). Thesecomponents have also been removed for clarity, but are readilyunderstood and available in the art. An illustrative ink path isindicated by the arrows (203).

The tubular body (113) is shown here to be straight. However, it will beunderstood that the tubular body (113) may be flexed or manipulated tofollow a nonlinear path as needed to accommodate other components withinthe interior of a printing device.

Referring now to FIG. 3, a diagram of an illustrative embodiment of anoptical transmitter (300) is shown. The optical transmitter (300) may beused in conjunction with a tubular body (113, FIG. 1) to transmit dataoptically through the tubular body (113, FIG. 1) to a correspondingreceiver. The optical transmitter (300) has a ring shape withsubstantially the same cross-sectional area as the tubular body (113,FIG. 1). The optical transmitter (300) includes a plurality of opticalsources (301, 303, 305) configured to transmit modulated optical beamsdirectly into the material of the tubular body (113, FIG. 1). Each ofthe optical sources (301, 303, 305) is configured to transmit opticalbeams having a specific characteristic wavelength (for example, λ₁, λ₂,λ₃, respectively). Each of the wavelengths ((λ₁, λ₂, λ₃) of opticalenergy may carry a separate channel of data to be transmitted to theoptical receiver. In the present example, multiple optical sources (301,303, 305) are disposed circumferentially about the body and regularlyalternate among three different types of optical sources (301, 303, 305)each configured to respectively transmit one of the three indicatedwavelengths (λ₁, λ₂, λ₃).

An optical source control line from the modulator element (119)corresponding to the first wavelength (λ₁) may be in communication witheach of the optical sources (301) configured to transmit at the firstwavelength (λ₁). In this way, all of the optical sources (301)configured to transmit optical energy at the first wavelength (λ₁) maytransmit substantially equivalent modulated optical beams concurrently.Similarly, optical sources (303) configured to transmit at the secondwavelength (λ₂) may transmit substantially equivalent modulated opticalbeams concurrently, and the optical sources (305) configured to transmitat the third wavelength (λ₃) may also transmit substantially equivalentmodulated optical beams concurrently.

Referring now to FIG. 4, another illustrative embodiment of a possibleoptical transmitter (400) is shown. The optical transmitter (400)includes three separate optical sources (401, 403, 405). Each of theoptical sources (401, 403, 405) is configured to transmit a modulatedoptical beam into the tubular body (113, FIG. 1) having a specificcharacteristic wavelength (λ₁, λ₂, λ₃, respectively).

As will be appreciated by those skilled in the art, while three types oftransmitters outputting three different respective wavelengths are shownin the examples of FIGS. 3 and 4, any number of different wavelengthsand corresponding transmitters may be used depending on the number ofdata channels desired. Moreover, different data channels may bedifferentiated by means other than distinct wavelength. For example,different data channels may be differentiated by beams of differentintensity, polarization, etc.

Referring now to FIG. 5, an illustrative embodiment of a possible system(500) for ink and multi-channel data delivery is shown. The system (500)includes a tubular body (113) configured to receive liquid ink from anink supply (101) and an ink pump (109) and provide a channel throughwhich the liquid ink may be delivered to a plurality of inkjet pens(521, 525, 529) in a printer.

The tubular body (113) is also configured to route data from printercontroller circuitry (123) to pen electronics (523, 527, 531) thatcontrol the operation of each of the inkjet pens (521, 525, 529,respectively).

The optical transmitter (111) in the system (500) is configured totransmit multiple channels of optical data into the tubular body (113),which conducts the optical data along its length to individual opticalreceivers (509, 511, 513) corresponding to the individual inkjet pens(521, 525, 529, respectively). In some embodiments, the opticaltransmitter (111) is a ring-shaped structure having substantially thesame cross-sectional shape and size as the tubular body (113). Theoptical transmitter may include one or more optical sources, such asLEDs, vertical cavity surface emitting lasers (VCSELs), other lasers,from which the optical beams bearing the data originate.

In some embodiments, the optical transmitter (111) may include aplurality of optical sources, each source being configured to transmitan optical beam of a different characteristic wavelength. Bytransmitting data from each of the optical sources through the tubularbody (113), multiple channels of data may be transmitted through thetubular body (113). In other embodiments, the optical transmitter (111)may include one or more optical sources that are configured toselectively alter the characteristic wavelength of optical beamsoriginating from the sources, thus allowing the sources to transmitoptical energy at one characteristic wavelength at a given time, andswitch to a separate characteristic wavelength at another time.

In the present example, different channels of optical data may beintended for, and received by, respective optical receivers (509, 511,513) of different inkjet pens (521, 525, 529, respectively). Bytransmitting multiple channels of optical data through the tubular body(113), a tubular body (113) that feeds ink from the same supply (101) todifferent inkjet pens (521, 525, 529) may transmit a separate datachannel to electronics (523, 527, 531) in each of the inkjet pens (521,525, 529).

Each optical receiver (509, 511, 513) is configured to only receive theoptical signal of the wavelength corresponding to the data channel forthe inkjet pen associated with that optical receiver. For example,optical filters may be present in the receivers (509, 511, 513),corresponding demodulator elements (515, 517, 519), and/or at the split(501) in the tubular body (113). The optical filters may filter out onlyoptical energy transmitted through the tubular body (113) that has acharacteristic wavelength corresponding to a data channel intended for arelated inkjet pen (521, 525, 529).

Referring now to FIG. 6, an illustrative embodiment of a system (600) ofhaving a visual diagnostic indicator on an inkjet pen (117) isdisplayed. When servicing an inkjet printer, service personnel oftenmust identify a faulty inkjet pen (117) from a group of inkjet penspresent in the printing device. In some cases, the printing device maybe equipped to identify an inkjet pen (117) that needs servicing to thetechnician. The present system (600) provides such a visual indicator toservice personnel. The system (600) illuminates a visual or an opticalindicator (603) on the inkjet pen (117) without requiring that aseparate LED or other illuminator be installed in the circuitry of thepen, thus freeing up valuable board real estate in the inkjet pen (117)

The system (600) includes a tubular body (113) that is configured totransport liquid ink from an ink supply (101) to an inkjet pen (117),where the ink may then be selectively applied to a print medium. Thetubular body (113) is coupled to an in-line ink pump (109) and anoptical source (601) at the first end. At the second end (107), thetubular body (113) includes an optical interface (602) to an internallight pipe and is coupled to the inkjet pen (117).

As described in relation to FIG. 1, the in-line ink pump (109) iscoupled to the ink supply (101) and is configured to mechanically forceliquid ink from the ink supply (101) into the first end of tubular body(113). By operation of the pump (109), the ink is provided underpressure to the inkjet pen (117) at the second end (107) of the tubularbody (113).

The tubular body (113) may be fabricated from a flexible material havingoptical properties that enable the transmission of light with nosignificant loss of energy. Upon entering this material that composesthe tubular body (113), the index of refraction of the material is suchthat substantially total internal reflection of the beam occurs, thusenabling the transmission of the optical beam along the length of thetubular body (113) with minimal losses. Many plastic materials havingsuch optical properties are available in the art. Additionally, customplastics or other materials having desirable optical characteristics foruse in the tubular body (113) may be used in some embodiments.

The optical source (601) of this example is configured to transmit avisible optical beam through the tubular body (113) to the opticalinterface (602) and into the visual indicator (603) which then appearsto be lit when examined by service personnel. Diagnostic circuitry (604)is configured to selectively activate at least one LED in the opticalsource (601) according to diagnostic circuitry in the printing device.For example, the diagnostic circuitry (604) may receive data from atleast one sensor in the printing device representative of the health ofa particular inkjet pen. When an inkjet pen (117) is performing poorlyor experiences a malfunction, the diagnostic circuitry (604) may thenselectively activate the LED(s) in the optical source (601) present inthe tubular body (113) connected to that particular inkjet pen (117),thereby illuminating the visual indicator (603) of the inkjet pen (117)and enabling service personnel to quickly identify the faulty inkjet pet(117).

The optical interface (602) is configured to route at least a portion ofthe optical beam received from the tubular body (113) to the opticalindicator (603) by way of an internal light pipe between the interface(602) and the visual indicator (603). The visual indicator (603) isoptically connected to the internal light pipe and includes atransparent material that allows light exiting from the internal lightpipe to shine through the visual indicator (603) so as to be seen fromoutside of the inkjet pen (117). The visual indicator (603) may be at areadily-visible location on the inkjet pen (117) and is then illuminatedby the optical beam from the source (601).

Furthermore, in some embodiments, the optical receiver (602) itself mayserve as a visual indicator. For example, portions of the opticalreceiver (602) may have a low index of refraction on the outer surfacerelative to that of the tube (113) such that light escapes through theouter periphery of the optical receiver (602). If the optical receiver(602) is near an inkjet pen (117), the optical receiver (602) may be anindicator for that pen (117).

Referring now to FIG. 7, a cross-sectional view of the system (600) isshown. Similar to the example of FIG. 2, illustrative paths (201, 202)of optical energy through the material of the tubular body (113) areshown as dotted lines going from the optical source (111) to the opticalinterface (602). In the present example, the optical receiver (602)routes the optical beams from the material of the tubular body (113)into the internal light pipe (703), which may be present inside thechannel defined by the tubular body (113). The optical beams are thenconducted to the optical indicator (603), which is illuminated by theoptical beam.

Referring now to FIG. 8, an illustrative system (800) that providesliquid ink, control data, and a diagnostic indication to an inkjet pen(117) is shown. The present system (800) combines the data transmissionand visual diagnostic indicator elements from previously describedembodiments. As described previously, the tubular body (113) isconfigured to transmit multiple channels of optical energy from theoptical transmitter (111).

Both diagnostic circuitry (604) and a printer controller module (123)are in communication with the optical transmitter (111). The diagnosticcircuitry (604) is configured to control the optical transmitter (111)to emit visible optical energy of a first characteristic wavelength whena malfunction in the pen (117) is detected.

In the present example, the optical receiver (115) includes an opticalinterface to an internal light pipe and is configured to transmitoptical beams having the first characteristic wavelength to a visualindicator (603), as previously described. Optical filters may be used toprevent optical beams of other channels (e.g., wavelengths) fromilluminating the visual indicator (603). Thus, when the optical energyof the first characteristic wavelength is transmitted, the opticalreceiver (115) routes the optical energy to the visual indicator (603)in the inkjet pen (117). Consequently, the visual indicator (603) isilluminated to indicate to service personnel that the pen (117) ismalfunctioning.

To transmit data from the printer controller (123) to the penelectronics (125), a second data channel, e.g., a second wavelength oflight, is used that will not be passed by the interface (115) into thevisual indicator (603). The printer controller module (123) isconfigured to modulate data into an optical beam having a secondcharacteristic wavelength emitted by the optical transmitter (111). Thismodulated beam is transmitted to the optical receiver (115) through thematerial of the tubular body (113). The first and second wavelengths aresufficiently distinct such that the components in the system (800) candistinguish between separate optical beams of the two wavelengths. Thus,light of the second wavelength is transmitted to the demodulator (121).The data from that optical beam is thus retrieved by the demodulator(121) and transmitted to the pen electronics (125).

Consequently, the system (800) can use two different wavelengths toselectively light the visual indicator (603) and transmit control datato the pen electronics (125). An optical signal for either purpose istransmitted through the tube (113) that also serves to deliver liquidink from the reservoir (101) to the inkjet pen (117). In someembodiments, non-visible wavelengths of light may be used for datatransmitted through the tubular body (113) to pen electronics (125), andvisible wavelengths of light may be used to illuminate the visualindicator (603). In this manner, the optical receiver (115) need notselectively block light of particular wavelengths.

In other embodiments, data may be transmitted to pen electronics (125)using a light signal with a magnitude, amplitude or intensity that ishigh enough to be detected by the optical receiver (121), but not highenough to be detected by the human eye at the visual indicator (603).When desired, the visual indicator (603) may be illuminated using a highmagnitude light signal.

Referring now to FIG. 9, an illustrative embodiment of a printing device(900) is shown. The printing device (900) is shown with a diagnosticvisual indicator (905) illuminated in an inkjet pen (903). The inkjetpen (903) is one of a group of inkjet pens (901) present in the printingdevice (900). As mentioned previously, the illuminated visual indicator(905) may help service personnel identify the faulty inkjet pen quicklyand efficiently.

Exemplary Methods

Referring now to FIG. 10, a flowchart of an illustrative embodiment of amethod (1000) of diagnostic indication in a printing device is shown.The method includes providing (step 1005) an optically transmissivetubular body between an ink supply and at least one inkjet pen in theprinting device. The tubular body is fabricated from a material havingsufficient optical properties to sustain total internal reflection ofoptical energy transmitted into the tubular body.

The method (1000) further includes identifying (step 1010) an inkjet penthat in the printing device that requires servicing. This may be done byevaluating sensor output in diagnostic circuitry. Visible light is thentransmitted (step 1015) from an optical source through the tubular bodyto the inkjet pen that requires servicing. The optical source may have asubstantially cylindrical geometry such that the cross-sectionalgeometries of the tubular body and the optical source may be coupledtogether and the visible light may be transmitted directly from theoptical source into the material of the tubular body.

The visible light may be routed from the tubular body to an internallight pipe in the inkjet pen. A visual indicator on the inkjet pen isthen illuminated (step 1020) with the visible light. The opticalilluminator may include a transparent material that transmits the lightexiting from the internal light pipe outside of the inkjet pen.Additionally, ink may be supplied through the tubular body from anoff-axis reservoir to the same inkjet pen.

Referring now to FIG. 11, a flowchart of an illustrative embodiment of amethod (1100) of ink and multi-channel data delivery is shown. Themethod (1100) includes providing (step 1105) an optically transmissivetubular body that defines an ink channel between an ink supply and atleast one inkjet pen. A plurality of channels of optical data aretransmitted (step 1110) along the length of the tubular body within thematerial of the tubular body. The multiple channels may be transmittedover a plurality of wavelengths of optical energy from at least oneoptical transmitter at one end of the tubular body.

The optical data are then received (step 1115) in a plurality of inkjetpens, with each of the inkjet pens having an optical receiver tuned to aspecific wavelength of optical energy used in the data transmission.Thus, in this example, each of the optical receivers is configured toreceive a different channel of optical data from the tubular body. Theoperation of the inkjet pens is then controlled (step 1120) by the datareceived at the optical receivers corresponding to each of the inkjetpens.

The preceding description has been presented only to illustrate anddescribe embodiments and examples of the principles described. Thisdescription is not intended to be exhaustive or to limit theseprinciples to any precise form disclosed. Many modifications andvariations are possible in light of the above teaching.

1. A system (100, 500, 600, 800) of ink and multi-channel data delivery,comprising: an optically transmissive tubular body (113) having at leasttwo ends (105, 107), said tubular body (113) defining an ink channelbetween an ink supply (101) and at least one inkjet pen (117, 521, 525,529, 901, 903); a multi-channel optical transmitter (111, 300, 400) inoptical communication with one end (105, 107) of said tubular body(113); and an optical receiver (115, 509, 511, 513) in opticalcommunication with another end (105, 107) of said tubular body (113). 2.The system (100, 500, 600, 800) of claim 1, wherein said opticaltransmitter (111, 300, 400) is configured to transmit separate channelsof optical data using substantially separate wavelengths of opticalenergy.
 3. The system (100, 500, 600, 800) of claim 1, wherein at leastone of said optical transmitter (111, 300, 400) and said opticalreceiver (115, 509, 511, 513) comprises a substantially cylindricalgeometry.
 4. The system (100, 500, 600, 800) of claim 1, furthercomprising a data source and a modulator (119) in communication withsaid optical transmitter (111, 300, 400) and a demodulator (121, 515,517, 519) and data recipient in communication with said inkjet pen (117,521, 525, 529, 901, 903) end.
 5. The system (100, 500, 600, 800) ofclaim 4, wherein said data source comprises an inkjet pen (117, 521,525, 529, 901, 903) controller and said data recipient comprises controlcircuitry in said inkjet pen (117, 521, 525, 529, 901, 903).
 6. Thesystem (100, 500, 600, 800) of claim 1, wherein said channel isconfigured to feed ink to each of a plurality of inkjet pens (117, 521,525, 529, 901, 903) disposed at a plurality of ends (105, 107) in saidtubular body (113).
 7. The system (100, 500, 600, 800) of claim 6,wherein each of said inkjet pens (117, 521, 525, 529, 901, 903)comprises an optical receiver (115, 509, 511, 513) tuned to receive onechannel transmitted by said optical transmitter (111, 300, 400).
 8. Asystem (100, 500, 600, 800) of diagnostic indication for an inkjet pen(117, 521, 525, 529, 901, 903), comprising: an optically transmissivetubular body (113) having at least two ends (105, 107), said tubularbody (113) defining an ink channel between an ink supply (101) and atleast one inkjet pen (117, 521, 525, 529, 901, 903); an optical source(301, 303, 305, 401, 403, 405, 601) in optical communication with oneend (105, 107) of said tubular body (113); an optical indicator (603,905) in optical communication with another end (105, 107) of saidtubular body (113), wherein said indicator (603, 905) is disposed onsaid inkjet pen (117, 521, 525, 529, 901, 903) and illuminable by anoptical beam transmitted from said optical source (301, 303, 305, 401,403, 405, 601); and control circuitry configured to activate saidoptical source (301, 303, 305, 401, 403, 405, 601) when said inkjet pen(117, 521, 525, 529, 901, 903) is determined to be faulty.
 9. The system(100, 500, 600, 800) of claim 8, wherein said tubular body (113) isconfigured to transmit separate channels of optical energy oversubstantially separate wavelengths of optical energy.
 10. The system(100, 500, 600, 800) of claim 9, further comprising an opticaltransmitter (111, 300, 400) in optical communication with said tubularbody (113), wherein said transmitter (111, 300, 400) is configured totransmit optical data through said tubular body (113) to an opticalreceiver (115, 509, 511, 513) corresponding to said inkjet pen (117,521, 525, 529, 901, 903).
 11. The system (100, 500, 600, 800) of claim8, further comprising a data source and a modulator (119) incommunication with said optical transmitter (111, 300, 400) and ademodulator (121, 515, 517, 519) and data recipient in communicationwith said inkjet pen (117, 521, 525, 529, 901, 903) end.
 12. The system(100, 500, 600, 800) of claim 11, wherein said data source comprises aninkjet pen (117, 521, 525, 529, 901, 903) controller and said datarecipient comprises control circuitry in said inkjet pen (117, 521, 525,529, 901, 903).
 13. The system (100, 500, 600, 800) of claim 8, whereinsaid inkjet pen (117, 521, 525, 529, 901, 903) comprises a diagnosticsensor (604) configured to detect faulty operation of said inkjet pen(117, 521, 525, 529, 901, 903).
 14. The system (100, 500, 600, 800) ofclaim 8, wherein said channel is configured to feed ink to each of aplurality of inkjet pens (117, 521, 525, 529, 901, 903) disposed at aplurality of ends (105, 107) in said tubular body (113).
 15. A method ofdiagnostic indication in a printing device (900), said methodcomprising: providing an optically transmissive tubular body (113)between an ink supply (101) and an inkjet pen (117, 521, 525, 529, 901,903) in said printing device (900); identifying an inkjet pen (117, 521,525, 529, 901, 903) that requires servicing; transmitting visible lightfrom an optical source (301, 303, 305, 401, 403, 405, 601) through saidtubular body (113); and illuminating an indicator (603, 905) on saidinkjet pen (117, 521, 525, 529, 901, 903) with said visible lightreceived in said inkjet pen (117, 521, 525, 529, 901, 903) through saidtubular body (113).
 16. The method of claim 15, wherein said tubularbody (113) comprises a material that sustains total internal reflectionof optical energy transmitted into the tubular body (113).
 17. Themethod of claim 15, wherein said method further comprises transmittingsaid visible light from said tubular body (113) to an internal lightpipe in said inkjet pen (117, 521, 525, 529, 901, 903).
 18. The methodof claim 17, wherein said optical illuminator comprises a transparentmaterial that transmits said light exiting from said internal light pipeoutside of said inkjet pen (117, 521, 525, 529, 901, 903).
 19. Themethod of claim 15, wherein said identifying an inkjet pen (117, 521,525, 529, 901, 903) comprises evaluating sensor output in diagnosticcircuitry (604).
 20. The method of claim 15, wherein said optical source(301, 303, 305, 401, 403, 405, 601) comprises a substantiallycylindrical geometry.